This invention refers to a disk for grinding concrete, specially designed to be applied to a concrete grinder, and more specifically, to allow the use of this type of disks on grinders with two propeller-shaped bases.
The application of this invention is in the construction area, especially in obtaining concrete floors with a perfect surface finish.
When preparing concrete pavement, the pouring of the raw material and its complementary vibrating are not sufficient to achieve a smooth enough surface, so when necessary, concrete grinders are used, based on a propeller-shaped base mechanism starting with rotating arms, generally four radial arms, so that the rotating action of these arms and their friction on the surface of the concrete grind this surface, to obtain the desired improved surface finish. In this sense, there are grinders with a single head and grinders with two, duly synchronized heads, whose arms cross each other, in other words, the distance between their rotational axes is substantially smaller than the sum of the radial dimension of two arms, to perform a joint function where the effect of one head partially overlaps the effect of the other. Obviously, to achieve this, the arms of one head must be angularly offset with respect to those of the other, which, in combination with their synchronized rotating motion, prevents these arms from interfering with each other.
A use of grinding disks is also known where, once the grinder has first been used with the disks, said disks are detached and the propeller-shaped bases alone are used, which helps give the concrete a better surface finish.
The grinding disks that are currently on the market are circular in shape, so that they can only be used on grinders with a single head, as on machines that have two heads these would interfere with each other since the disks have to work on the same plane, making normal operation of the machine impossible.
The disk that the invention proposes resolved the aforementioned problem in a fully satisfactory manner, so that, while performing satisfactorily as a grinding element, it can be used on grinders with either one or two heads.
More specifically, to achieve this, the disk that the invention proposes, starting with an imaginary circle, has four ample indentations, equiangularly distributed and curved-concave, which convert it into a type of xe2x80x9ccross,xe2x80x9d with equal arms, in the shape of an isosceles trapezoid with slanting, curved-concave sides, so that the curvature and radius of these indentations roughly coincides with the radius of the disk itself, which, by means of proper angular offsetting between the two disks mounted on a grinder with two heads, prevents said disks from touching each other, as each arm of one of them fits into the respective indentation of the other, and vice-versa.